1. Field of the Invention
The present invention relates to surgical repair of fractures, deformities, diseases and surgical osteotomies of bone. More particularly, the present invention relates to a method and apparatus for mandibular osteosynthesis in which a portion of the mandible is resected to make way for subsequent bone grafting.
2. Discussion of the Related Art
In various craniofacial surgical procedures, it is necessary to align and secure two bone portions in a relatively fixed relationship to each other. As examples, the need to establish such a secured relationship can arise from a fracture of the bone or from an oncology resection of the bone. To ensure that the bone can regenerate in the proper orientation and fuse the fracture, or maintain mandibular shape after an oncology resection, it is important that the bone portions be fixed in the desired position.
It is known in the art to provide metal plates for the repair of bone fractures. Such plates generally are secured to bone portions with fasteners, especially screws. Among other applications, such plates and fasteners are used to provide rigid stabilization of craniofacial fractures and oncology resections. The plates conventionally employed for cranial and facial osteosynthesis generally comprise small, generally flat, elongated sections of metal. The plate sections contain round and perhaps elongated screw holes at various points along their lengths for receiving screws to fasten the plate sections to bone.
Because no surface of the human skeleton is completely flat, existing plates must be extensively twisted, formed and bent during surgery to conform to portions of the skeleton on which they are to be affixed. Significant time is expended during surgery shaping and re-shaping metal plates to conform adequately to bone surfaces. This expenditure of time increases anesthesia requirements and operating room time and also increases the potential for infection.
In one commonly used technique for mandibular reconstruction, an initially flat plate is bent to conform to the contours of the surface of the mandible. The conformed plate is secured to the mandible by a plurality of screw fasteners received through holes in the plate. The screw fasteners penetrate into and gain purchase in the bone. Subsequently, the fasteners and plate are removed to allow surgical access to the mandible, e.g., to remove a cancerous growth, leaving a gap in the mandible. Finally, the plate is fastened again to the mandible by engaging the fasteners with the previously formed holes in the mandible. The bone gap in the mandible is left alone. After a wait of an appropriate time, e.g., 6-24 months, to make sure that the cancer has not returned, a bone graft is placed in the gap. During the months of waiting in which the gap is open, soft tissue grows into the gap and rubs against the plate, causing soft tissue irritation, or dehiscence.
While known systems utilizing plates and fasteners for cranial and facial osteosynthesis have proven to be acceptable for certain applications, such systems are nevertheless susceptible to improvements that may enhance their performance. Known systems do not provide plates having enhanced screw placement options together with enhanced bending ease at desired locations, while preserving the integrity of screw holes at bending sites and avoiding interference between screws in adjacent screw holes. Known systems also do not provide a way to prevent the ingrowth of soft tissue into the gap in the mandible left by resection of cancerous bone. These and other desirable improvements are provided by the present invention, preferred embodiments of which are described below with reference to the drawings.
According to one aspect of the present invention, an apparatus for osteosynthesis of a mandible includes an elongated plate having a plurality of apertures and a cover having a lateral wall, a top wall, and a medial wall defining a channel. The elongated plate is received within the channel of the cover.
According to another aspect of the present invention, a method of surgically repairing a mandible includes the steps of providing an elongated plate having a plurality of apertures, and providing a fastener having means for engaging the mandible and having means for engaging an aperture of the plate. The elongated plate is secured to the mandible with the fastener. A cover is provided having a lateral wall, a top wall, and a medial wall defining a channel. A portion of the mandible is resected leaving a bony gap. The elongated plate is received within the channel, and the cover is received within the bony gap.
It is an object of the present invention to provide an osteosynthesis plate for use in surgical repair of a mandible and to alleviate growth of soft tissue into a gap in the mandible left by surgical resection of the mandibular bone and to alleviate dehiscence of such soft tissue by protecting the plate from contact by such soft tissue.
It is a further object of the present invention to alleviate growth of soft tissue into a gap in the mandible left by surgical resection of the mandibular bone.
Additional objects and advantages of the present invention will be apparent from the descriptions below of preferred embodiments and their methods of use, made with reference to the drawings.